1. Field
One or more embodiments are directed a method and system of processing a multi-energy X-ray image.
2. Description of the Related Art
A system of processing a multi-energy X-ray image may acquire an X-ray image having at least two energy bands. In general, since differing materials are respectively seen as having unique X-ray attenuation characteristics in different energy bands, a separation of images for each material may be performed using the X-ray attenuation characteristics.
X-rays are widely used to detect masses that may represent cancer, while a system having high sensitivity may be required to make the determination of whether the mass is malignant. However, in an actual clinical diagnosis, such a high specificity in combination with high sensitivity is not available. Typically, such specificity is only obtained by an invasive biopsy to distinguish between a benign lesion or mass and a malignant lesion or mass, which may have substantial impact on patients. Thus, when it is difficult to distinguish between the benign lesion or mass and the malignant lesion or mass through current X-ray examinations, an invasive biopsy that excises a tissue from a suspicious area for examination may be required. Accordingly, detecting the malignant lesion or mass in human tissues through a non-invasive way using only X-ray image processing may be more desirable.
Recently, a cancer diagnosis performed using an X-ray image processing system is primarily conducted based on the detected shape of a mass, such as of a lesion. Since benign lesions or masses do not invade surrounding tissues, boundaries with surrounding tissues are likely to be smooth and rounded-shaped. Conversely, in a case of the malignant lesion or mass, the boundaries with surrounding tissues may be observed to be rough or non-smooth. Occasionally, a lesion or mass having the rounded shape may also turn out to be the malignant lesion or mass.
In general X-ray image processing is defined herein as being different from a three-dimensional (3D) X-ray Computed Tomography (CT) image processing, as the X-ray imaging processing bases observations on X-ray images where all pieces of depth direction data are overlapped. The three-dimensional (3D) X-ray Computed Tomography (CT) image processing would provide separate images for separate depths. Accordingly, when such a depth overlapping X-Ray imaging processing is used to detect whether a lesion or mass is benign or malignant, the boundary of the benign/malignant lesion tumor may be inaccurately identified due to other overlapping tissues that are different from the tissue of the examined lesion or mass and which may merely be at a different depth from the mass, e.g., either above or below.
In addition, an X-ray system can obtain images more quickly than the three-dimensional (3D) X-ray Computed Tomography (CT) image processing and thus, dynamics between images may be more easily observed with an X-ray system. Accordingly, the present inventors have found that there is a demand for a new X-ray image processing approach having both a high sensitivity and a high specificity, without the costs and time drawbacks of current systems.